1. Field of the Invention
The present invention relates to a dental implant and more particularly to an endo-osseous implant inserted and embedded in gingiva and dental alveoli.
2. Description of the Related Art
Histologically stable adhesion of an endo-osseous implant to gingiva and dental alveoli against the occlusal pressure is essential for successful dental implant.
Some methods have been proposed to enhance the binding force of an endo-osseous implant: for example, forming grooves on the side wall of the implant as disclosed in Japanese Patent Laying-Open Gazette No. Hei-1-135346; and coating the implant with porous substance to increase the surface area in contact with the dental alveoli as disclosed in Japanese Patent Laying-Open Gazette No. Hei-1-164359.
In the former method, occlusal pressure from plural directions triggers unfavorable fracture of dental alveoli, which exceeds the physiological limit of absorption and neogenesis, adjacent to the grooves of the implant. Such fracture eventually causes removal of the implant from the dental alveoli. In the latter method, the larger surface area in contact with the dental alveoli ensures stable adhesion of the implant. Occlusion may, however, disturb the normal circulation of tissues inserted in the porous substance to necrose and putrefy the tissues and thereby cause inflammation of gingiva. The inflammation increases the internal pressure of the implant and lowers the adhesion of the implant to gingiva. In extreme cases, the implant is to be removed from the dental alveoli and gingiva by operation.